Pressure-reducing valve for air-feed drills.



' A. mun-0R & L. 0. BAYLES. PBESSUBBYBBPUGING VALVE FOR AIR FEED DRILLS.Ar'rtioluron 11.21) MAR. 20, 1912.

Patented Feb. 10, 1914. ]I[ J Fig. 2. 12 11 A TTORNEY ing is aspecification. v

This invention relates to a pressure re- UNITED STACFES PATENT oFFIoE;

ALBERT I-I. TAYLOR ANDLEWIS c. BAYLES, or nAsroiv. PENNSYLVANIA,AssIqNoRs T0 INGERSOLL-BAND COMPANY. or NEW YORK, N..Y. A CORPORATION 0FNEW JERSEY.

PRESSURE-REDUCING VALVE ron AIR-FEED nniLLs.

To all whom it may concern Be it known that We. ALBERT ll. TAYLOR andLEWIS C. Barnes, citizens of the United States, residing-at Easton, 1nthe-county of Northampton and State of Pennsylvania,- have inventedcertain new andu ser'ul lin- ')rovements in Pressure-Reducing Valves forAir-Feed Drills, of which the follo vducing device for use with air feedfluid Drills of this kind'consist piston in a cylinder in line with thedrill, the air pressure being taken direct from the supplypipeoperating-the drill. In such a machine the force with which thedrill is fed is dependent on the diameter of thepiston in the feedingcylinder. .II" this piston is sufficiently large to properly support thedrill when boring a vertical ,"up hole as in the roof of ajsto'pe, thereWill be a large excesspressure when boring a horizontal or flat hole,and a still greater excess pressure in boring a down hole. Also ifthesame directionv is maintained and the air' pressure varied the drillWill be fed forward various less stringent conditions.

with difierent force. Onac'co-unt of this'difference in feeding powerrequired; it is necessary for a. given type of drill to build]difierentsizes of air feeds, and to supply various difierent sizes forvarious conditions. The object of this invention is to prov de a valvebetween the main feed supply andthe air feed cylinder which can beadjusted to reduce the pressure in the air feed for A I l the feedcylinder leads to the-back of the valve ton elearancc which maintained adrill is furnished with cylinder sul'licientl i large to meet themostdifficult case, the feedcan be ad usted down to adapt it t We areaware that reducing known Where the pressure of t' livered to the airfeed is va tion to the fluid furnished to t i do not contemplate adevice o1: however. in the present device. A will. maintain ajllFEILPl'tbSlll'il in teed cylinder re of the pr the air sup nidingthis exec pressure for i; the valve is set.

l ith this object in view. we ha devised x a valve a practicaleuihothnient of which is Specification of Letters Patent. Patented Feb.1D, 1914; Application filed March 20,1912. SerialNo. 68?,106. I?

shown in' the accompanying dravvings in Figure l is an elevation of thecomplete yalve section lookin rom thea r fetid 6X 'inderside.

' In the embodiment shown in the draw in'gs, the complete drillingmachine com.-

prises a separate disk like -valve"seetion 1 which is ofsueh ator n asto lit, and be secured byholts 2 through bolt holes 3 between the headblock 4: of ,a'usual formof drill provided with a usual air inlet 5, andthe head I a pressure reducing valve is not desired.

The valve chest 1 is pierced in a diametral direction by a cylindricalbore 8 with a slightly contracted portion in whichis seated the spoolvalve 9 so that it can slide freely 59 either direction. The-spool valvef9 has acontracted portlonrlO-whlch is al ways in 7 communication with aport 11.

which "is in free con'imunication .with the port-l2 leading from thein-let5. vFrom the other side of the bore at such a point that'it willhe closed by slight movement of the spool valve O'is a port 13lcadinginto the air feed cylinder 6. A second poi-F14 from all times bya lmss 15 on a nut 16, Which is .hrcadcd mm the end of valve bore 8. On

5 the other side of the spoc-lfvalve isfa'sprlng.

'hich. 'uesses the valve toward the at fjltudluul grooves inthe bore andactuated hv. a threaded spindle 20. mounted to turn 1 freely in a nut21. threaded in the end of l the valve bore.

' 3 its j vent port 23 lead from the bore 8 just inl ide the nut 21. tothe atmosphere;

The operation of the valve is are-follows:- Fiunpmc the valve spool tobe in the posi- The spindle is provided on outer end with a thumb screw229 1;

v v vertical sectionthrough thevalve on the line 'IIII of Fig. at. Fig.3

and is ZHllHsELtlDl'V compressed by a pluml5 pim-ided Wl'tll lugs 19sliding in lontion shown in Fig. 2 which will be the case l when the airpressure is not on in the drill. When the air is now turned on, it willpass through ports 12, 11, 13 into the air feed cylinder. Since theclearance back of the valve spool is open to the feed cylinder pressurethrough port l4=, and the'bore 8. on l the other side of-the spool isopen to the atmosphere through port 23, there will be a l fluid pressureon the back of the spool tend- F ing-to close the port 13, whichpressure is l balanced by the pressure of the spring 17 on the otherside of the spool \valve. When the f pressure on the back of-the spoolreaches a certain point it will overcome the pressure of the spring andclose the port 13. -This 5 point of closingis determined by the compression of the spring 17' which can bej changed by adjusting theposition of plun- 9 ger 18. Itwill- .be seen, therefore, that, thespring-17 can be adjusted for any desired pressure int-he air" feedcylinder and this l will be maintained as long as the pressure in thedrill is above this desired pressure. j

It is to be understood that the present disclosure shows only oneembodiment and} changed and modified forms of the device are consideredwithin the sgirit-and scopeset of our invention as expres \Vhat weclaim-is:

1. In combination, a fluid operatedgdmll in the claims.

having a head block, an air feed cylinder forsaid drill having a headblock adapted to fit ders of an air feed drill 3. As an article ofmanufacture, a valve chest of disk like form containing a pressure.reducing "alve, -said valvechest being adapt. t ed to be secured betweenthe drill and air feed cylinders of; anair feed drill.

ALBERT H..TAYLOR. LEWIS C. BAYLES. WVitnesses G. D; PA'rrERsoN, H; D.MAXWELL.

Copies of this patent may "be obtained for five cents each, by,addressing the Commissioner of Patents; Washington, D. 0.

